1. Field of the Invention
The present invention relates to a capacitive dynamic quantity sensor for detecting angular velocity or acceleration of an automobile or the like and a semiconductor device for converting an image of an object into a video signal.
2. Description of the Related Art
FIG. 18 shows a conventional capacitive dynamic quantity sensor. A capacitive dynamic quantity sensor for acceleration 507 includes a lower glass plate 501, a silicon plate 502, and an upper glass plate 503, which are laminated. The silicon plate 502 has a weight 521 which is displaced due to acceleration applied thereto and a column 522 which is necessary to reduce a size of the sensor and electrically connects a capacitance detection electrode 511 provided on the lower glass plate 501 with an electrode 535 provided outside the upper glass plate 503. The upper glass plate 503 has an electrode 531 for detecting displacement of the weight 521 due to the acceleration as a change in capacitance. The lower glass plate 501 has the electrode 511 for detecting displacement of the weight 521 due to the acceleration as a change in capacitance. The column 522 located in the silicon plate 502 is formed by laser processing or etching and generally separated from the weight (For example, see, Masayoshi Esashi, “Micromachining and micromachine”, The Institute of Electrical Engineers of Japan, Volume 114-A, Number 7/8, 1994) However, when the column is formed, it is necessary to separate the column from other members by etching or the like after it is temporarily fixed to a glass substrate by anode bonding or the like. Consequently, a surface of the electrode patterned on the glass plate is also subjected to an unintended etching process and the like, with the result that problems occur with respect to the improvements of mass productivity and reliability.
Even in the case where the column is not fixed to the glass plate or the like by anode bonding, when the column is mechanically separated from other members, a main body portion and the column cannot be electrically connected with each other. When devices are formed on both surfaces of the glass plate, an electrical signal cannot be led from a device formed on one surface. Thus, a structure capable of leading electrical signals from the devices formed on both surfaces is required for mounting, thereby increasing a manufacturing cost.